Out of (one's) mind (used as an adjective or adverb)
Situation #1: Two friendsEdward: What's going on with Tom? He's acting weird.
Jean: Oh, he's completely out of his mind right now. His girlfriend dumped him, and now he's acting crazy. But he'll be fine once he calms down.
Explanation: To be "out of (one's) mind" means that the person is not thinking clearly, and usually suggests that the person is acting crazy, as in the example above. In addition, the expression can be altered with certain words for additional meanings, as seen below:
Situation #2: Two friends
Frances: Do you have any plans tonight?
Bill: No, and I'm bored out of my mind! What's going on?
Frances: Let's get dinner then.
Explanation: To be "bored out of (one's) mind" means to be extremely bored.
Situation #3:Two friends
Kim: How was the party last night?
Jack: Not great. Steve got drunk out of his mind, and he tried to start a fight at the bar, so I had to give him a ride home.
Explanation: To be "drunk out of (someone's) mind" means to be extremely drunk, usually to the level that the person will not remember his/her actions the following day.